User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-14
4) Backplane bus module
BCPM commu nicates with other boards in the BTS baseband part through
backplane bus, including control information communication with BCKM and traffic
data communication with E1 interface board.
5) Clock module
The clock module performs double-frequency phase-locking to the clock signals
from the backplane, provides clock for boards, and drives and co-phases the clock
signals generated on the local board, to get satisfactory clock signals.
6) Power supply module
It performs DC/DC power conversion from +27V to 3.3V.
III. Interface
l
High-speed data bus interface
Interface with BRDM.
l
Backplane bus interface
Interface with other boards of baseband part
l
RS232 serial port
As an emergency serial port, it is connected with UART as a standby node, used for
communicating with BCKM when other part of the board is faulty.
IV. Index
The board size is 460mm
%
233.35mm, powered with +27V, power consumption
<30W.
2.2.5 Resource Distribution Module (BRDM)
I. Overview
BRDM is logically located between BTRM and BCPM, providing path for orthogonal
data connection (IQ) and exchange between the two so as to support the flexible
configuration relation between BCPM and BTRM. BRDM also support daisy chain
cascading between BCPMs.
Data from BTRM are sent to BRDM through optical fiber. BRDM distributes the data
before sending them to BCPMS via the high-speed data bus. BRDM can also build
daisy chains for BCPMs. BRDM connects via the short daisy chain provided to the
BCPM to form standard daisy chain. This can help to improve the utilization ratio of
